A Method of Assessing Acoustical Two-Port Properties of Earplugs

An experimental setup for objective measurements of high impedance objects in ducts, yielding the acoustical two-port properties of the object, is presented. The setup has been applied on earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent duplicating the outer ear of a person. The insertion loss is considered to give the acoustical properties of the object. Such a setup, however, gives a ratio of the 'response of a system' to that of another system. The actual properties of the object are thereby embedded in a complicated artificial response. By instead fitting the test object in a duct, it's two-port parameters can be assessed, given... (More)

An experimental setup for objective measurements of high impedance objects in ducts, yielding the acoustical two-port properties of the object, is presented. The setup has been applied on earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent duplicating the outer ear of a person. The insertion loss is considered to give the acoustical properties of the object. Such a setup, however, gives a ratio of the 'response of a system' to that of another system. The actual properties of the object are thereby embedded in a complicated artificial response. By instead fitting the test object in a duct, it's two-port parameters can be assessed, given the sound pressure level at both sides of the object for two sufficiently diiferent termination impedances. (Less)

@misc{68aba96f-659e-4f8b-b1a7-361dcd670e63,
abstract = {An experimental setup for objective measurements of high impedance objects in ducts, yielding the acoustical two-port properties of the object, is presented. The setup has been applied on earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent duplicating the outer ear of a person. The insertion loss is considered to give the acoustical properties of the object. Such a setup, however, gives a ratio of the 'response of a system' to that of another system. The actual properties of the object are thereby embedded in a complicated artificial response. By instead fitting the test object in a duct, it's two-port parameters can be assessed, given the sound pressure level at both sides of the object for two sufficiently diiferent termination impedances.},
author = {Hiselius, Per},
issn = {0281-8477},
keyword = {flow impedance,dynamic flow resistance,objective measurement,equivalent circuit,insertion loss,earplugs,HPD,hearing protectors,protection,hearing,attenuation,two-port,four-pole},
language = {eng},
publisher = {ARRAY(0x9f07c20)},
title = {A Method of Assessing Acoustical Two-Port Properties of Earplugs},
volume = {TVBA-3115},
year = {2002},
}